Centrifugal high gradient magnetic separation of fine ilmenite

Abstract

High gradient magnetic separation (HGMS) has been an effective method for the concentration or removal of fine para-magnetic particles from suspension, but its powerful magnetic capture to magnetic particles results in the mechanical entrainment of non-magnetic particles in magnetic product, and thus reduces the separation selectivity. HGMS in centrifugal field (CHGMS) is proposed to improve the separation selectivity, and in this investigation a cyclic pilot-scale CHGMS separator was used to concentrate fine ilmenites from slurry. The theoretical descriptions on this CHGMS process indicate that the introduction of centrifugal field in the HGMS field has a promoting effect on the magnetic capture of matrix to magnetic particles and significantly improves the HGMS performance, and a minimum critical magnetic field force is required for the capture of magnetic particles in the centrifugal field. These theoretical descriptions were experimentally verified and the dependence of CHGMS performance on the key parameters such as centrifugal acceleration was determined. This CHGMS method has achieved a significantly improved separation selectivity and performance to the fine ilmenite, and thus provided a potential prospect in the development of CHGMS technology.